Resilient shaft coupling

ABSTRACT

A resilient shaft coupling wherein a pair of hub members is tied together for torque transmission by a flexible coupling member Ushaped in cross section and having generally the configuration of an automotive tire. Each hub member is provided with a torquetransmitting gear in mating engagement with a cooperating torquetransmitting gear on each of a pair of flange portions of the coupling member. The coupling is further provided with additional means for precluding disengagement of the mating torquetransmitting gears, and any undesired relative movement thereof. For these reasons the coupling allows transmission of relatively larger blocks of power than possible with comparable prior art resilient couplings, and transmission of blocks of power at higher numbers of revolution per unit of time than possible with comparable prior art resilient couplings.

1111 tates atent Srhlotmann et al. [451 .1111 :1 1%, 1972 1 RESILENTSHAFT COUPLING 2,952,143 9/1960 Case ..64/11 [72] Inventors: KarlSchlotmann, jaegerweg l3; Heilm 3,313,124 4/ 1967 Fllepp ..64/1 1Dieter- Bohm, Peukinger Weg 18, both of Pflma Examiner xennethw s [a e475 Unna; Werner Ruggen, Lessingstrasse Attongy Erwin Seller p gu 7,4757 Holzwickede, all of Germany [22] Filed: Apr. 8, 1970 ABSTRACT [21]A L N 31,044 A resilient shaft coupling wherein a pair of hub members istied together for torque transmission by a flexible coupling memberU-shaped in cross section and having generally the [30] ForeignAplflimuon Priority Data configuration of an automotive tire. Each hubmember is pro- Apr. 4, 1969 Germany ..P'19 18 621.1 vided with aOrqwmsmitfing gear in mating engagement with a cooperatingtorque-transmitting gear on each of a pair [52] of flange portions ofthe coupling member. The coupling is [51] further provided withadditional means for precluding disen- 58] gagement of the matingtorque-transmitting gears, and any undesired relative movement thereof.For these reasons the coupling allows transmission of relatively largerblocks of [56] References Cited power than possible with comparableprior art resilient couplings, and transmission of blocks of power athigher num- UNITED STATES PATENTS bers of revolution per unit of timethan possible with comparable prior art resilient couplings. 2,867,1021/1959 Williams ..64/1l 3,137,149 6/1964 Schlotmann ..64/1 1 10 Claims,4 Drawing Figures RESILIENT SHAFT couruuc BACKGROUND OF INVENTION Priorart couplings of the aforementioned description are subject to atendency of partial separation of their cooperating torque-transmittinggears. This limitation becomes more apparent when it is desired totransmit a relatively large torque from one shaft to another coaxiallyarranged shaft, or when both shafts to be coupled for joint motion aresubjected to large angular velocities resulting in large centrifugalforces.

The principal object of the present invention is to provide resilientshaft couplings which are not subject to the aforementioned limitations,or drawbacks, and more particularly to provide resilient shaft couplingshaving entirely conforming mating torque-transmitting parts whose shapeand position are not significantly changed under the action of externalforces, including centrifugal forces, and thus retain their perfectmating engagement under various and the most onerous operatingconditions. The means provided by the invention to achieve the aboveends do not call for exertion of excessive pressures on the resilientparts of couplings, and more particularly on the resilient couplingmember thereof which is generally made of natural or a synthetic rubber,and should not be subjected to excessive pressures.

Another object of the invention is to provide flexible shaft couplingswhich have the above desirable performance characteristics, and whichlend themselves to be assembled in a particularly simple fashion, thusminimizing the cost of installation and maintenance.

Still another object of the invention is to provide improved resilientshaft couplings including a resilient or flexible coupling member havingflanges with torque-transmitting gears which flanges are supported at aplurality of spaced critical points against the action of centrifugalforces.

SUMMARY OF INVENTION Resilient or flexible couplings embodying thisinvention include a pair of aligned shaft-receiving hub members eachhaving a torque-transmitting gear on the radially outer side thereof.Such couplings further include a resilient annular coupling membersurrounding said pair of hub members. The coupling member has a pair ofaxially outwardly projecting flanges each overlapping one of said pairof hub members.

Each of said pair of flanges has a torque-transmitting gear on theradially inner side thereof in mating engagement with saidtorque-transmitting gear on the radially outer side of each of said pairof hub members. The coupling further includes a pair of annular clampingmeans each mounted on the radially outer side of one of said pair offlanges of said coupling member.

The essence of the present invention consists in the arrangement ofscrew studs for securing the aforementioned annular clamping means tothe coupling in such a way that they project through said pair offlanges of said coupling member at regions of said pair of flanges wherethe latter are reinforced by toroidally shaped keys or tongues engagingcorresponding toroidally shaped recesses in said pair of flanges.

BRIEF DESCRIPTION OF DRAWINGS FIG. ll illustrates a coupling embodyingthe present invention, the upper part of FIG. 1 showing the coupling inlongitudinal cross section, and the lower part of FIG. 1 showing thecoupling in elevation or front view;

FIG. 2 shows partly in side elevation and partly in vertical section amodification of one of the annular clamping means of the couplingaccording to FIG. 1; and

FIGS. 3-4 each show in vertical section another modification of thestructure of FIG. 1, each figure being limited to the left portion ofthe coupling, the right portion thereof being of the same nature as itsleft portion.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Referring now tothe drawings, and more particularly to FIG. 1 thereof, referencecharacter 1 has been applied to indicate a resilient annular couplingmember of rubber or the like elastomer which has substantially the shapeof an automotive tire, i.e. it is substantially U-shaped in crosssection. Coupling member 1 and a pair of axially outwardly projectingflanges 2 thereof may be made either of natural or synthetic rubber, andthey may include one or more reinforcement inserts of a textile material(not shown). Each flange 2 of coupling member 1 is provided with atorque-transmitting gear 3 including a plurality of straight gear teethwhich are arranged in a cylindrical pattern around the axis of thecoupling.

The coupling further includes a pair of coaxial, spaced hub members 5 ofwhich each is substantially in the shape of a ho]- low cylinder andintended to be mounted on a pair of shafts (not shown) to be coupled.Each of hub members 5 has a torque-transmitting gear 4 on the radiallyouter surface thereof. The teeth of gear 4 are straight and form acylindrical pattern around the axis of the coupling. Gears 3 and 4 arein engagement so that torques can be transmitted from one hub member 4to the other hub member 4 by the intermediary of coupling member 1 andthe flanges 2 thereof overlapping hub members 5. The preferredconfiguration of the teeth constituting gear 4 is also more fullydisclosed in our aforementioned copending patent application to whichreference may be had in regard to the preferred configuration of theteeth of gears 3 and 4.

It will be apparent from FIG. 1 that the axial length of the teeth ofgears 4 exceeds the axial length of the teeth of gears 3, and that gears3 are arranged in such a way relative to gears 4 that the teeth of gears4 project on both sides beyond the end surfaces of the teeth of gears 3.

Such a coupling requires further for the provision of means formaintaining gears 3, 4 in torque-transmitting engagement mainly againstthe action of centrifugal forces. To this end the coupling includes apair of annular clamping means 8 each mounted on the radially outer sideof one of the pair of flanges 2 of coupling member 1. These annularclamping means 8 may be tightened by conventional fastener means asshown more in detail in our above-referred-to copending patentapplication. Each of the annular clamping means 8 of FIG. 1 is formed bya pair of complementary semicircular elements tied together at thejunctions thereof by screw-threaded studs 9 arranged in a plane at rightangles to the common axis of coupling member 1 and hub members 5.Reference characters 11 have been applied to indicate recesses inannular clamping means 8 for receiving the heads of the clamping screws9 for annular clamping means 8.

The radially outer surfaces of flanges 2 of coupling member 1 areprovided with recess means 6 and projections I0 solid with annularclamping means b enter into recess means 6 to maintain firm engagementbetween torque-transmitting gears 3 and 4. In the particular embodimentof the invention shown in FIG. 1 each of recess means 6 is formed by atoroidally shaped groove in the outer surface of each flange 2, and eachof the aforementioned projections 10 is formed by a toroidally shapedtongue being a part of each flange 2 and projecting into theaforementioned groove. Clamping screws 9 project through toroidallyshaped tongues 10, i.e., the shafts of screws 9 are surrounded at aportion of the length thereof by the material of which the toroidallyshaped tongues 10 of annular clamping means 8 are made. This greatlyincreases the mechanical strength or dimensional stability of theclamping structure of flanges 2. The presence of mating parts 6, 10greatly reduces the danger of separation of flanges 2 and gears 3 fromgears 4 of hub members 5 at the particular point where parts 6, 10 arelocated.

It will be apparent that the more screws 9 are tightened, the higher thepressure which is exerted radially inwardly by annular clamping means 8.Screw-threaded studs 9 may be arranged relatively close to thelongitudinal axis of the coupling. In the structure shown the largestradius of the coupling is the outer radius of the center portion ofcoupling member 1, and the spacing of screw-threaded studs 9 from theaxis of the coupling is less than the firstmentioned radius. As aresult, the bulk of the coupling tends to be small, and the ends ofscrewthreaded studs 9 do not project radially outwardly beyond thegeneral outline of the coupling, thus avoiding the danger of injury tooperating personnel by outwardly projecting parts of the coupling Asshown in FIG. 1 each of the pair of flanges 2 is provided with a pair oftoroidally shaped grooves 6 and 7, and each annular clamping means 8 isprovided with a pair of toroidally shaped tongues 10 and 12. Tongues 10project into grooves 6 and tongues 12 project into grooves 7. The medianplanes of grooves 6 and 7 of each flange 2 enclose an acute angle, andthe median planes of tongues 10 and 12 of each annular clamping means 8enclose the same acute angle as the median planes of grooves 6 and 7.Grooves 7 and tongues 12 tend to preclude a disengagement of gears 3 and4 in the region where flanges 2 project at substantially right anglesfrom the center portion of coupling member 1. At this point thecentrifugal forces to which coupling member 1 is subjected areparticularly large. Hence the provision of means precluding separationof gears 3 and 4 is particularly important at the points of junction offlanges 2 with the center portion of coupling member 1.

Coupling member 1 may have a radial slit as explained more in detail inour copending patent application to which reference is made above. Inthe particular structure shown in FIG. 1 the coupling member 1 and itsflange 2 do not require a radial slit for mounting the same on hubmembers 5. Coupling member 1 and its flanges 2 may be mounted on hubmembers 5 merely by sliding the former on the latter in the direction ofthe common axis thereof. The omission of a mounting slit in couplingmember 1 and its flanges 2 is desirable wherever the torque to betransmitted by the coupling is relatively large, or the number ofrevolution per minute to which the coupling will be subjected isrelatively high.

FIG. 2 shows a modification of the annular clamping means 8 of FIG. Iand this modification is intended to be combined with a pair ofshaft-receiving hub members and with a flanged coupling member in theway shown in FIG. 1. The structure of FIG. 2 includes in addition to thetoroidally shaped tongue 10 which is arranged approximately midwaybetween the axially outer end and the axially inner end of annularclamping means 8, and in addition to the toroidally shaped tongue 12bothof which are substantially the same as the toroidally shaped tongues 10,12 of FIG. la third toroidally shaped tongue 13. The median plane oftoroidally shaped tongue 13 is substantially coaxial with hub members 5of FIG. 1 and adapted to engage the radially outwardly extending centerportion of coupling member 1. To this end the point of the centerportion of coupling member 1 juxtaposed to tongue 13 ought to beprovided with a toroidally shaped groove (not shown) conforming to theshape of toroidally shaped projection or key 13. Toroidally shapedprojection or key 13 forms a support for the center portion of couplingmember 1 in an area where it is subjected to particularly highcentrifugal forces. The provision of projection or key 13 makes itpossible to operate the coupling at relatively large numbers ofrevolutions per minute, all other circumstances remaining unchanged.

The coupling of FIG. 3 is similar to that of FIG. 1, but differs fromthat of FIG. 1 inasmuch as the former dispenses with toroidally shapedgroove 7 at the junction of the center portion of coupling member I andthe flange 2 of coupling member 1 and of a toroidally shaped key orprojection 12 mating with groove 7. The structure of FIG. 3 differsfurther from that of FIG. I by the addition in the former of disk-shapedabutment 14 on the axially inner end surface of each hub member 5,limiting axial movement of each of the pair of flanges 2 of couplingmember 1 relative to the pair of hub members 5. The

structure of FIG. 3 is desirable on account of its great simplicity, butit is only suited for relatively nononerous operating conditions. Thepresence of abutment disks 14 which may be welded to hub members 5preclude mounting of the coupling member 1 with its flanges 2 by anaxial movement thereof relative to hub members 5. In the structure ofFIG. 3 the coupling member 1 and its flanges 2 must be formed by twoseparate complementary parts, or it must at least be provided with aradial slit to make it possible to mount it on hub members 5. This tendsto decrease the mechanical strength of the structure, but its greatsimplicity still makes it desirable in instances where mechanicalstrength is not of prime importance.

The structure of FIG. 4 includes two toroidally shaped projections orkeys 10, 12 integral with the annular clamping means 8 and twotoroidally shaped grooves 6, 7 formed by coupling member 1 and itsflanges 2. The annular clamping means 8 have a radially inwardlyextending projection 15, the radially inner end of which forms a gearwhose constituent teeth have axially inner end surfaces which arejuxtaposed to the axially outer end surfaces of the teeth forming gear3. To achieve this end the radially inner portion of projection 15 has asystem of gear teeth 18 which is virtually congruent with the system ofgear teeth 4 formed by hub member 5. This makes it possible to arrangeduring assembly of the coupling each of the teeth of gear system 18 inregistry with the teeth of gear system 4, and each of the spaces betweenthe teeth of gear system 18 in registry with the spaces between theteeth of gear system 4. In this position the unit formed by couplingmember 1 and its flanges 3 and annular clamping means 8 may be mountedon hub members 5 by a movement of parts 1, 2 and 8 relative to parts 5in a direction of the axis of the coupling. When this has been achieved,annular clamping means 8 may be rotated about the axis of the couplingso as to move the axially inner end surfaces of the system of teeth 18to a position in which they are juxtaposed to the axially outer endsurfaces of the constituent teeth of the gear 3. This precludes anyundesired axial relative movement of gears 3 and 18. When gear 18 hasbeen moved to the abutment position thereof it must be retained in thatposition by appropriate fastener means or, in other words, any rotarymotion thereof which might move it out of its abutment position must beprecluded. In FIG. 6 reference numeral 17 has been applied to a dottedline indicating diagrammatically such a fastener means projectingradially through projection 15 of annular clamping means 8 into hubmember 5. Fastener means 17 may, for instance, be a setscrew. If desiredthe axially outer end of each hub member 5 may be provided with anannular groove (not shown) into which the radially inner end ofprojection 15 extends. Such an arrangement facilitates the rotary motionof parts 8, l5, 18 from their position of registry to the abutmentposition or locking position thereof.

It will be apparent from the above that the rotation feature of thestructure of FIG. 6 is in effect that of a bayonet-type fastener.

It will be apparent from the above and in particular from the drawingsthat in all the preferred embodiments of the invention the toroidal keysor tongues 10 are substantially semicircular in cross section and thatthe straight axes of studs 9 extend tangentially to the circular axes ofkeys or tongues 10.

It will be further apparent from the above that the projections 12 ofthe structures of FIGS. 1, 2 and 4 are substantially claw shaped andoperate in the fashion of claws or talons projecting into couplingmember 1 and its flange 2. The relative positions of keys 10 and claws12 is crucial as far as the performance characteristics of the couplingare concerned. To be more specific, tongues or keys 10 ought to bepositioned approximately midway between the axially outer ends and theaxially inner ends of clamping means of clamping rings 8 and claws ortalons 12 ought to be arranged closer to the median plane of couplingmember 1 than parts 10.

The setscrew 17 or the like of FIG. 4 is a releasable fastener meanswhich selectively allows and precludes rotary motions of clamping meansor clamping rings 8 relative to hub members 5.

Referring to H6. 2, the relative positions of projections 10, 12 and 13is of considerable importance. Projection l3 and the point where itengages coupling member 1 are more remote from the axis of couplingmember 1 than tongue and projection 12 and the points where parts 10 and12, respectively, engage coupling member 1.

All of the embodiments of the invention shown have the common feature,though in varying degrees, of allowing coupling of relatively largeblocks of power and are suitable for transmission of large torques.These couplings may be applied in instances where prior art resilientshaft couplings including systems of cooperating torque-transmittinggears cannot be applied.

We claim as our invention:

1. A resilient shaft coupling including a pair of aligned shaftreceivinghub members each having a torque-transmitting gear on the radially outerside thereof, a resilient annular coupling member surrounding said pairof hub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, each of said pair of flanges of saidcoupling member being provided at the radially outer side thereof with atoroidally shaped groovelike recess, a pair of annular radiallysubdivided clamping means each mounted upon said radially outer side ofone of said pair of flanges of said coupling member, each of said pairof clamping means having a toroidally shaped tongue engaging saidtoroidally shaped groovelike recess in one of said pair of flanges ofsaid coupling member; and screw studs for tightening said pair ofclamping means arranged in planes defined by said toroidal groovelikerecess and by said toroidally shaped tongue, said screw studs extendingthrough said pair of flanges of said coupling member at points whereeach of said pair of flanges is reinforced by said toroidally shapedtongue thereof.

2. A resilient shaft coupling as specified in claim 1 wherein saidtoroidally shaped tongue is arranged approximately midway between theaxially outer end and the axially inner end of each of said pair ofannular clamping means, and wherein each of said pair of annularclamping means is provided with a projection in addition to toroidallyshaped tongue engaging said coupling member and arranged closer to themedian plane of said coupling member than said toroidally shaped tongue.

3. A resilient shaft coupling including a pair of aligned shaftreceivinghub members each having a torque-transmitting gear on the radially outerside thereof, a resilient annular coupling member surrounding said pairof hub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, and a pair of annular clamping means eachmounted on the radially outer side of said pair of flanges of saidcoupling member wherein each of said pair of flanges of said couplingmember is provided with a pair of coaxial toroidal grooves on theradially outer surface thereof, wherein each of said pair of annularclamping means is provided with a pair of toroidal tongues projectinginto said pair of toroidal grooves in one of said pair of flanges ofsaid coupling member, wherein the median planes of said pair of toroidalgrooves of each of said pair of flanges of said coupling member enclosea first acute angle, and wherein the median planes of said pair oftoroidal tongues of each of said pair of annular clamping means enclosea second acute angle equal to said first acute angle.

4. A resilient shaft coupling including a pair of aligned shaftreceivinghub members each having a torque-transmitting gear on the radially outerside thereof, a resilient annular coupling member surrounding said pairof hub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, each of said pair of flanges of saidcoupling member being provided on the radially outer side thereof with atoroidal groove and a pair of annular clamping means each mounted on theradially outer side of said pair of flanges of said coupling member,each provided with a toroidal tongue projecting into said toroidalgroove in one of said pair of flanges of said coupling member whereinsaid toroidal groove is arranged substantially at the point where eachof said pair of flanges projects from said coupling member, and whereinsaid toroidal tongue is arranged immediately adjacentto the axiallyinner end of each of said pair of annular clamping means.

5. A resilient shaft coupling as specified in claim 3 wherein each ofsaid pair of annular clamping means is provided with an additionaltoroidally shaped tongue having a median plane substantially coaxialwith said pair of hub members adapted to engage a radially outwardlyextending portion of said coupling member.

6. A resilient shaft coupling including a pair of aligned shaftreceivinghub members each having a torque-transmitting gear on the radially outerside thereof, a resilient annular coupling member surrounding said pairof hub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, each of said pair of flanges being providedwith recess means on the radially outer surface thereof, and a pair ofannular clamping means each mounted on the radially outer side of saidpair of flanges of said coupling member, and each including a projectionengaging said recess means to maintain a firm engagement between saidpair of flanges and said pair of hub members, each of said pair ofannular clamping means being further provided adjacent the axially outerend thereof with a radially inwardly extending projection engaging theaxially outer end surfaces of said torque-transmitting gear of one ofsaid pair of flanges of said coupling member and fastener meansextending radially through each of said pair of annular clamping meansand having a radially inner end engaging one of said pair of hub membersto preclude rotation of each of said pair of annular clamping meansrelative to one of said pair of hub members.

7. A resilient shaft coupling as specified in claim 2 wherein saidprojection is in the shape of a claw penetrating into said couplingmember.

8. A resilient shaft coupling as specified in claim 7 wherein each ofsaid pair of clamping means further includes a projection engaging thesurface of said coupling member at a point more remote from the axis ofsaid coupling member than said toroidally shaped tongue and more remotefrom the axis of said coupling member than said projection in the shapeof a claw.

9. A resilient shaft coupling as specified in claim 1 wherein each ofsaid pair of clamping means is provided with a system of gears havingend surfaces in registry with the end surface of saidtorque-transmitting gear on one of said pair of hub members, and whereineach of said pair of clamping means is provided with a releasablefastener means for selectively allowing and precluding rotary motions ofsaid pair of clamping means relative to said pair of hub members.

10. A resilient shaft coupling as specified in claim 1 wherein saidtoroidally shaped tongue of each of said pair of clamping means issubstantially semicircular in cross section, and wherein the axis ofeach of said screw studs engages tangentially the axis of saidtoroidally shaped tongue of one of said clamping means.

1. A resilient shaft coupling including a pair of aligned shaftreceivinghub members each having a torque-transmitting gear on the radially outerside thereof, a resilient annular coupling member surrounding said pairof hub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, each of said pair of flanges of saidcoupling member being provided at the radially outer side thereof with atoroidally shaped groovelike recess, a pair of annular radiallysubdivided clamping means each mounted upon said radially outer side ofone of said pair of flanges of said coupling member, each of said pairof clamping means having a toroidally shaped tongue engaging saidtoroidally shaped groovelike recess in one of said pair of flanges ofsaid coupling member; and screw studs for tightening said pair ofclamping means arranged in planes defined by said toroidal groovelikerecess and by said toroidally shaped tongue, said screw studs extendingthrough said pair of flanges of said coupling member at points whereeach of said paiR of flanges is reinforced by said toroidally shapedtongue thereof.
 2. A resilient shaft coupling as specified in claim 1wherein said toroidally shaped tongue is arranged approximately midwaybetween the axially outer end and the axially inner end of each of saidpair of annular clamping means, and wherein each of said pair of annularclamping means is provided with a projection in addition to toroidallyshaped tongue engaging said coupling member and arranged closer to themedian plane of said coupling member than said toroidally shaped tongue.3. A resilient shaft coupling including a pair of alignedshaft-receiving hub members each having a torque-transmitting gear onthe radially outer side thereof, a resilient annular coupling membersurrounding said pair of hub members and having a pair of axiallyoutwardly projecting flanges each overlapping one of said pair of hubmembers and each having a torque-transmitting gear on the radially innerside thereof in mating engagement with said torque-transmitting gear onthe radially outer side of said pair of hub members, and a pair ofannular clamping means each mounted on the radially outer side of saidpair of flanges of said coupling member wherein each of said pair offlanges of said coupling member is provided with a pair of coaxialtoroidal grooves on the radially outer surface thereof, wherein each ofsaid pair of annular clamping means is provided with a pair of toroidaltongues projecting into said pair of toroidal grooves in one of saidpair of flanges of said coupling member, wherein the median planes ofsaid pair of toroidal grooves of each of said pair of flanges of saidcoupling member enclose a first acute angle, and wherein the medianplanes of said pair of toroidal tongues of each of said pair of annularclamping means enclose a second acute angle equal to said first acuteangle.
 4. A resilient shaft coupling including a pair of alignedshaft-receiving hub members each having a torque-transmitting gear onthe radially outer side thereof, a resilient annular coupling membersurrounding said pair of hub members and having a pair of axiallyoutwardly projecting flanges each overlapping one of said pair of hubmembers and each having a torque-transmitting gear on the radially innerside thereof in mating engagement with said torque-transmitting gear onthe radially outer side of said pair of hub members, each of said pairof flanges of said coupling member being provided on the radially outerside thereof with a toroidal groove and a pair of annular clamping meanseach mounted on the radially outer side of said pair of flanges of saidcoupling member, each provided with a toroidal tongue projecting intosaid toroidal groove in one of said pair of flanges of said couplingmember wherein said toroidal groove is arranged substantially at thepoint where each of said pair of flanges projects from said couplingmember, and wherein said toroidal tongue is arranged immediatelyadjacent to the axially inner end of each of said pair of annularclamping means.
 5. A resilient shaft coupling as specified in claim 3wherein each of said pair of annular clamping means is provided with anadditional toroidally shaped tongue having a median plane substantiallycoaxial with said pair of hub members adapted to engage a radiallyoutwardly extending portion of said coupling member.
 6. A resilientshaft coupling including a pair of aligned shaft-receiving hub memberseach having a torque-transmitting gear on the radially outer sidethereof, a resilient annular coupling member surrounding said pair ofhub members and having a pair of axially outwardly projecting flangeseach overlapping one of said pair of hub members and each having atorque-transmitting gear on the radially inner side thereof in matingengagement with said torque-transmitting gear on the radially outer sideof said pair of hub members, each of said pair of flanges being providedwith recess means on the radially outer surface thereof, and a pair Ofannular clamping means each mounted on the radially outer side of saidpair of flanges of said coupling member, and each including a projectionengaging said recess means to maintain a firm engagement between saidpair of flanges and said pair of hub members, each of said pair ofannular clamping means being further provided adjacent the axially outerend thereof with a radially inwardly extending projection engaging theaxially outer end surfaces of said torque-transmitting gear of one ofsaid pair of flanges of said coupling member and fastener meansextending radially through each of said pair of annular clamping meansand having a radially inner end engaging one of said pair of hub membersto preclude rotation of each of said pair of annular clamping meansrelative to one of said pair of hub members.
 7. A resilient shaftcoupling as specified in claim 2 wherein said projection is in the shapeof a claw penetrating into said coupling member.
 8. A resilient shaftcoupling as specified in claim 7 wherein each of said pair of clampingmeans further includes a projection engaging the surface of saidcoupling member at a point more remote from the axis of said couplingmember than said toroidally shaped tongue and more remote from the axisof said coupling member than said projection in the shape of a claw. 9.A resilient shaft coupling as specified in claim 1 wherein each of saidpair of clamping means is provided with a system of gears having endsurfaces in registry with the end surface of said torque-transmittinggear on one of said pair of hub members, and wherein each of said pairof clamping means is provided with a releasable fastener means forselectively allowing and precluding rotary motions of said pair ofclamping means relative to said pair of hub members.
 10. A resilientshaft coupling as specified in claim 1 wherein said toroidally shapedtongue of each of said pair of clamping means is substantiallysemicircular in cross section, and wherein the axis of each of saidscrew studs engages tangentially the axis of said toroidally shapedtongue of one of said clamping means.